JP6679730B2 - Sulfide solid electrolyte - Google Patents

Description

  The present invention relates to a sulfide solid electrolyte, an electrode mixture and a lithium ion battery.

With the rapid spread of information-related devices such as personal computers, video cameras, and mobile phones and communication devices in recent years, development of batteries used as power sources thereof has been emphasized. Among these batteries, lithium-ion batteries are drawing attention because of their high energy density.
Since lithium-ion batteries currently on the market use an electrolytic solution containing a flammable organic solvent, a safety device that suppresses the temperature rise at the time of a short circuit is attached and the structure and materials are improved to prevent short circuits. Is required. On the other hand, a lithium-ion battery in which the electrolyte is changed to a solid electrolyte to solidify the battery does not use a flammable organic solvent in the battery, so the safety device can be simplified and the manufacturing cost and productivity can be improved. Is considered to be excellent.

As a solid electrolyte used in a lithium ion battery, a sulfide solid electrolyte is known. Various crystal structures of sulfide solid electrolytes are known, and as one of them, there is an argyrodite crystal structure (Patent Documents 1 to 5 and Non-Patent Documents 1 to 3).
The aldilodite crystal structure is a crystal with high stability, and there are also crystals with high ionic conductivity. However, it is required to develop a mass-production method and further improve the ionic conductivity.

Japanese Patent Publication No. 2010-540396 International Publication WO2015 / 011937 International Publication WO2015 / 012042 JP 2016-24874 A International Publication WO2016 / 104702

Angew. chem Vol. 47 (2008), no. 4, P. 755-758 Phys. Status. Solidi Vol. 208 (2011), no. 8, P. 1804 to 1807 Solid State Ionics Vol. 221 (2012) P. 1-5

  One of the objects of the present invention is to provide a novel sulfide solid substance having a high ionic conductivity and including an aldyrodiite type crystal structure.

According to one embodiment of the present invention, lithium, phosphorus, sulfur,
Including one or more elements X selected from the group consisting of chalcogen elements other than sulfur and halogen elements,
Including an aldilodite type crystal structure,
The molar ratio a (Li / P) of lithium to phosphorus, the molar ratio b (S / P) of sulfur to phosphorus, and the molar ratio c (X / P) of the element X to phosphorus are represented by the following formulas (1) to A sulfide solid electrolyte satisfying (3) is provided.
5.0 ≦ a ≦ 7.1 (1)
1.0 <ab = 1.5 (2)
6.5 ≦ a + c <7.1 (3)
(In the formula, b> 0 and c> 0 are satisfied.)

  According to one embodiment of the present invention, it is possible to provide a novel sulfide solid electrolyte having a high ionic conductivity and including an aldilodite type crystal structure.

3 is an X-ray diffraction pattern of the intermediate product obtained in Example 1. 3 is an X-ray diffraction pattern of the sulfide solid electrolyte obtained in Example 1. 9 is an X-ray diffraction pattern of the mixed powder of Comparative Example 7.

The sulfide solid electrolyte according to one embodiment of the present invention contains lithium, phosphorus, sulfur, and one or more elements X selected from the group consisting of chalcogen elements and halogen elements other than sulfur. Then, the molar ratio a (Li / P) of lithium to phosphorus, the molar ratio b (S / P) of sulfur to phosphorus, and the molar ratio c (X / P) of element X to phosphorus are represented by the following formulas (1) to ( 3) is satisfied.
5.0 ≦ a ≦ 7.1 (1)
1.0 <ab = 1.5 (2)
6.5 ≦ a + c <7.1 (3)
(In the formula, b> 0 and c> 0 are satisfied.)

The stoichiometric composition of a sulfide solid electrolyte containing a general aldyrodiite crystal is represented by Li _7-x PS _6-x X _x . The sulfide solid electrolyte of this embodiment has a composition different from a general composition. When the composition deviation of S is α and the composition deviation of X is β, the composition of the sulfide solid electrolyte of the present embodiment is represented by Li _7-x PS _{6-x + α} X _{x + β} . In this case, a−b in the above formula (2) becomes a−b = 7−x− (6−x + α) = 1−α, which is a value that correlates with the composition shift of S, and is represented by the above formula (3). A + c is a + c = 7−x + x + β = 7 + β, which is a value that correlates with the composition deviation of X.
1.0 <ab = 1.5 in the formula (2) becomes 1.0 <1-α <≦ 1.5, and when the formula is further modified, −0.5 ≦ α <0. That is, the sulfide solid electrolyte of the present embodiment is a sulfide solid electrolyte in which a part of S (sulfur) is deficient as compared with a general sulfide solid electrolyte containing aldyrodiite crystals.

Examples of the chalcogen element excluding sulfur include oxygen (O), selenium (Se), tellurium (Te), and the like.
Further, examples of the halogen element include F, Cl, Br, I and the like.
The above formula (2) is preferably 1.0 <ab ≦ 1.4, and more preferably 1.0 <ab ≦ 1.3.
The above formula (3) is preferably 6.7 ≦ a + c <7.1, and more preferably 6.85 ≦ a + c <7.1.
In the sulfide solid electrolyte of the present embodiment, the above formula (1) and the above formula (2) satisfy 1.0 <ab−b ≦ 1.5 and the above formula (3) satisfies 6.5 ≦ a + c <7.1. In some cases, the ionic conductivity is 5.1 mS / cm or more. When 1.0 <ab−b ≦ 1.4 in the above formulas (1) and (2) and 6.7 ≦ a + c <7.1 in the above formulas (3), the ionic conductivity is 5. It can be increased to 8 mS / cm or more. Furthermore, when the above formulas (1) and (2) are 1.0 <ab−1.3, and the above formula (3) is 6.85 ≦ a + c <7.1, the ionic conductivity is It can be further increased to 6.9 mS / cm or more.

The molar ratio and composition of each element in the sulfide solid electrolyte can be measured by ICP emission spectrometry. The measuring method of ICP emission spectrometry is described in Examples.
The molar ratio of each element can be controlled by adjusting the content of each element in the raw material.

The smaller the ionic radius of the element X, the more the element X contained in the aldyrodiite type crystal structure and the higher the ionic conductivity. Therefore, the molar ratio a of lithium to phosphorus can be adjusted by the ionic radius of the element X. preferable. The element X can be classified into the following _three groups (X ₁ , X ₂ and X ₃ ) according to the size of the ionic radius.
X ₁ : F, Cl, O
X ₂ : Br
X ₃ : I, Se, Te
In the element X, when the molar ratio occupied by the element X ₁ is the largest, the above formula (1) is preferably 5.2 ≦ a ≦ 6.5, and preferably 5.25 ≦ a ≦ 6.4. Is more preferable. Further, in the element X, when the molar ratio occupied by the element X ₂ is the largest, the above formula (1) preferably satisfies 5.2 ≦ a ≦ 6.8, and 5.3 ≦ a ≦ 6.6. More preferably. Further, in the element X, when the molar ratio occupied by the element X ₃ is the largest, the above formula (1) preferably satisfies 5.5 ≦ a ≦ 7.0, and 5.5 ≦ a ≦ 6.8. More preferably.

The element X is preferably composed of only a halogen element.
The phosphorus is an element that constitutes the skeletal structure of the sulfide solid electrolyte.

The sulfide solid electrolyte of the present embodiment includes an aldyrodiite type crystal structure. A part of the sulfide solid electrolyte may have an aldilodite type crystal structure, or all of the sulfide solid electrolyte may have an aldyrodite type crystal structure.
The sulfide solid electrolyte of the present embodiment has a diffraction peak at 2θ = 25.2 ± 0.5 deg and 29.7 ± 0.5 deg, for example, in powder X-ray diffraction measurement using CuKα ray, and thus has a aldyrodite structure. It can be determined to have a type crystal structure. The diffraction peaks at 2θ = 25.2 ± 0.5 deg and 29.7 ± 0.5 deg are peaks derived from the aldilodite type crystal structure. Arujirodaito type crystal structure, and PS ₄ ^3- of the unit structure of the main skeleton, a structure surrounded by elemental sulfur lithium element (Li) around its (S) or halogen element (X) is arranged.
The diffraction peaks of the aldilodite type crystal structure are, for example, 2θ = 15.3 ± 0.5 deg, 17.7 ± 0.5 deg, 31.1. It may appear in ± 0.5 deg, 44.9 ± 0.5 deg, and 47.7 ± 0.5 deg. The sulfide solid electrolyte of this embodiment may have these peaks.

  In the present application, the position of the diffraction peak is determined to be A ± 0.5 deg when the median value is A, but it is preferably A ± 0.3 deg. For example, in the case of the diffraction peak of 2θ = 25.2 ± 0.5 deg described above, the median value A is 25.2 deg, and it is preferable that the median value A exists in the range of 2θ = 25.2 ± 0.3 deg. The same applies to determination of all other diffraction peak positions in the present application.

  Examples of the aldilodite type crystal structure include the crystal structures disclosed in Non-Patent Documents 1 to 3, JP 2010-540396 A, JP 2011-096630 A, and JP 2013-211171 A. it can.

  The sulfide solid electrolyte of the present embodiment may include a crystal structure other than the aldilodite type crystal structure. In general, various crystal components and amorphous components are mixed in the sulfide solid electrolyte. In the present embodiment, the sulfide solid electrolyte containing a crystal structure is a sulfide solid electrolyte in which a peak derived from the sulfide solid electrolyte is observed in the X-ray diffraction pattern in the X-ray diffraction measurement. It is also possible that residual raw materials are included.

  The sulfide solid electrolyte of the present embodiment may contain elements such as Si, Ge, Sn, Pb, B, Al, Ga, As, Sb, and Bi in addition to the above lithium, phosphorus, sulfur and element X. Good. In the case where the sulfide solid electrolyte contains one or more elements M selected from the group consisting of Si, Ge, Sn, Pb, B, Al, Ga, As, Sb and Bi, in (1) to (3) above. The molar ratio of each element is the molar ratio with respect to the total of the element M and phosphorus. For example, the molar ratio a (Li / P) of lithium to phosphorus is Li / (P + M).

The sulfide solid electrolyte of the present embodiment preferably satisfies, for example, the composition represented by the following formula (4).
Li _a (P _1-z M _z ) S _b X _c (4)
(In the formula, M is one or more elements selected from the group consisting of Si, Ge, Sn, Pb, B, Al, Ga, As, Sb and Bi, and X is F, Cl, Br, I. , O, Se, and Te are one or more elements selected from the group consisting of a to c satisfying the above formulas (1) to (3), and z is 0 ≦ z ≦ 0.3.

In the formula (4), when the molar ratio of the element X _{1 to} the whole X is largest, a is preferably 5.2 ≦ a ≦ 6.5, and 5.25 ≦ a ≦ 6.4. More preferably. When the molar ratio occupied by the element X ₂ is the largest, a is preferably 5.2 ≦ a ≦ 6.8, more preferably 5.3 ≦ a ≦ 6.6. When the molar ratio of the element X ₃ is the largest, a is preferably 5.5 ≦ a ≦ 7.0, and more preferably 5.5 ≦ a ≦ 6.8.

X in formula (4) is preferably one or more halogen elements selected from F, Cl, Br and I. As a result, the halogen element is incorporated into the aldilodite type crystal structure, and the ionic conductivity is increased. When two or more halogen elements are contained, the content ratio of each element is not limited.
z is preferably 0.

In the powder X-ray diffraction using CuKα ray, the sulfide solid electrolyte of the present embodiment has diffraction peaks at 2θ = 17.6 ± 0.4 deg and 2θ = 18.1 ± 0.4 deg (aldirodite type crystal structure). It is preferable that the following formula (5) is satisfied.
_{0 <I A / I B <} 0.05 (5)
(In the formula, I _A represents the intensity of a diffraction peak of 2θ = 17.6 ± 0.4 deg and 2θ = 18.1 ± 0.4 deg which is not the diffraction peak of the aldyrodiite type crystal structure, and I _B represents 2θ = It represents the intensity of the diffraction peak at 29.7 ± 0.5 deg.)

Crystal structure identified by I _A (hereinafter. Referred to Li ₃ PS ₄ crystal structure) are the low ionic conductivity, lowering the ionic conductivity of the solid electrolyte. The above formula (5) represents that the amount of Li ₃ PS ₄ crystal structure is relatively small as compared with the aldilodite type crystal structure. Equation (5) _is, 0 _<more preferably _I A / _I B _<0.03, even more preferably from _{0 <I A / I B <} 0.02.
Either 2θ = 17.6 ± 0.4 deg or 2θ = 18.1 ± 0.4 deg may not be measured because it usually overlaps with the diffraction peak of the aldilodite type crystal structure having a relatively high peak intensity. Therefore, the one which is not the diffraction peak of the aldyrodite type crystal structure among 2θ = 17.6 ± 0.4 deg and 2θ = 18.1 ± 0.4 deg is usually the weakest of the two observed peaks. Means one.

  The sulfide solid electrolyte of the present embodiment is a production method having a step of producing an intermediate by reacting a mixture of raw materials described later by applying mechanical stress, and a step of heat-treating the intermediate to crystallize it. Can be manufactured by.

  As the raw material to be used, two or more kinds of compounds or simple substances containing the elements that the sulfide solid electrolyte to be produced essentially contains, that is, lithium, phosphorus, sulfur and the element X as a whole, are used in combination.

Examples of the raw material containing lithium include lithium compounds such as lithium sulfide (Li ₂ S), lithium oxide (Li ₂ O) and lithium carbonate (Li ₂ CO ₃ ), and simple lithium metal. Of these, lithium compounds are preferable, and lithium sulfide is more preferable.
The lithium sulfide can be used without any limitation, but a high purity one is preferable. Lithium sulfide can be produced, for example, by the method described in JP-A-7-330312, JP-A-9-283156, JP-A-2010-163356, and JP-A-2011-84438.
Specifically, lithium hydroxide and hydrogen sulfide are reacted at 70 ° C. to 300 ° C. in a hydrocarbon-based organic solvent to produce lithium hydrosulfide, and then this reaction liquid is desulfurized by sulfidation. Lithium can be synthesized (JP 2010-163356A).
In addition, lithium hydroxide and hydrogen sulfide are reacted in an aqueous solvent at 10 ° C. to 100 ° C. to generate lithium hydrosulfide, and then the reaction solution is dehydrosulfided to synthesize lithium sulfide. JP 2011-84438 A).

Examples of the raw material containing phosphorus include phosphorus sulfide such as phosphorus trisulfide (P ₂ S ₃ ), phosphorus pentasulfide (P ₂ S ₅ ), phosphorus compounds such as sodium phosphate (Na ₃ PO ₄ ), and Examples include phosphorus alone. Among these, phosphorus sulfide is preferable, and phosphorus pentasulfide (P ₂ S ₅ ) is more preferable. The phosphorus compound such as diphosphorus pentasulfide (P ₂ S ₅ ) and the simple substance of phosphorus can be used without limitation as long as they are industrially produced and sold.

The raw material containing the element X preferably contains, for example, a halogen compound represented by the following formula (6).
M _l- X _m (6)

In the formula (6), M is sodium (Na), lithium (Li), boron (B), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), germanium (Ge), arsenic. (As), selenium (Se), tin (Sn), antimony (Sb), tellurium (Te), lead (Pb), bismuth (Bi), or a combination of these elements with an oxygen element or a sulfur element , Lithium (Li) or phosphorus (P) is preferable, and lithium (Li) is more preferable.
X is a halogen element selected from fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).
In addition, 1 is an integer of 1 or 2, and m is an integer of 1 to 10. When m is an integer of 2 to 10, that is, when there are a plurality of Xs, Xs may be the same or different. For example, SiBrCl ₃ described later has m of 4 and X is composed of different elements of Br and Cl.

Specific examples of the halogen compound represented by the above formula (6) include sodium halides such as NaI, NaF, NaCl and NaBr; lithium halides such as LiF, LiCl, LiBr and LiI; BCl ₃ and BBr _3. , BI _{3 and} other boron halides; AlF ₃ , AlBr ₃ , AlI ₃ , and aluminum halides such as AlCl ₃ ; SiF ₄ , SiCl ₄ , SiCl ₃ , Si ₂ Cl ₆ , SiBr ₄ , SiBrCl ₃ , and SiBr ₂ Cl ₂ , SiI ₄ and halogenated _{silicon; PF 3, PF 5, PCl} 3, PCl 5, POCl 3, PBr 3, POBr 3, PI 3, P 2 Cl 4, P 2 I 4 halogenated such as phosphorus; SF ₂ , SF ₄ , SF ₆ , S ₂ F ₁₀ , SCl ₂ , S ₂ Cl ₂ , S ₂ Br _2, etc. Sulfur: GeF ₄ , GeCl ₄ , GeBr ₄ , GeI ₄ , GeF ₂ , GeCl ₂ , germanium halide such as GeBr ₂ , GeI ₂ ; AsF ₃ , AsCl ₃ , AsBr ₃ , AsI ₃ , halogenated AsF _5, etc. _{; SeF 4, SeF 6, SeCl} 2, SeCl 4, Se 2 Br 2, SeBr 4 halogenated such as _{selenium; SnF 4, SnCl 4, SnBr} 4, SnI 4, SnF 2, SnCl 2, SnBr 2, SnI 2 , etc. halogenated _{tin; SbF 3, SbCl 3, SbBr} 3, SbI 3, SbF 5, SbCl 5 halogenated and _{antimony; TeF 4, Te 2 F 10} , TeF 6, TeCl 2, TeCl 4, TeBr 2, TeBr 4 halogenated tellurium such as TeI _4; PbF _4, PbCl _{4 PbF 2, PbCl 2, PbBr 2} , PbI 2 , etc. lead halide _{of; BiF 3, BiCl 3, BiBr} 3, BiI 3 halogenated bismuth, etc., and the like.

Among them, lithium halides such as lithium chloride (LiCl), lithium bromide (LiBr) and lithium iodide (LiI), phosphorus pentachloride (PCl ₅ ), phosphorus trichloride (PCl ₃ ), phosphorus pentabromide (PBr _5). ) And phosphorus halides such as phosphorus tribromide (PBr ₃ ). Among them, lithium halides such as LiCl, LiBr and LiI and PBr ₃ are preferable, lithium halides such as LiCl, LiBr and LiI are more preferable, and LiCl and LiBr are further preferable.
As the halogen compound, one of the above compounds may be used alone, or two or more may be used in combination. That is, at least one of the above compounds can be used. In this case, the halogen element may be used alone or in combination of two or more of the above halogen elements.

  In the present embodiment, a lithium compound, a phosphorus compound, and a halogen compound are contained, and it is preferable that at least one of the lithium compound and the phosphorus compound contains an elemental sulfur, and a combination of lithium sulfide, phosphorus sulfide, and lithium halide is more preferable. A combination of lithium sulfide, phosphorus pentasulfide and lithium halide is more preferable.

In the present embodiment, mechanical stress is applied to the above raw materials to react with each other to form an intermediate. Here, “applying mechanical stress” means mechanically applying a shearing force, an impact force, or the like. Examples of means for applying mechanical stress include a crusher such as a planetary ball mill, a vibration mill, and a rolling mill, and a kneader.
In the conventional technology (for example, Patent Document 2), the raw material powder is pulverized and mixed to such an extent that the crystallinity can be maintained. On the other hand, in the present embodiment, it is preferable that a mechanical stress is applied to the raw material to react the raw material to obtain an intermediate containing a glass component. That is, due to the mechanical stress stronger than that of the conventional technique, at least a part of the raw material powder is pulverized and mixed until the crystallinity cannot be maintained. As a result, the PS ₄ structure, which is the basic skeleton of the aldyrodite type crystal structure, can be produced in the intermediate stage, and the halogen can be highly dispersed. As a result, in the heat treatment of the next step, when the aldilodite type crystal structure that is a stable phase is formed, halogen is easily incorporated into the aldyrodite type crystal structure. Further, it is presumed that a low ionic conduction phase such as a Li ₃ PS ₄ crystal structure is unlikely to occur because the phase does not pass through different regions. From this, it is estimated that the sulfide solid electrolyte of the present embodiment exhibits high ionic conductivity.
The presence of the glass (amorphous) component in the intermediate can be confirmed by the presence of a broad peak (halo pattern) due to the amorphous component in XRD measurement.
Further, the sulfide solid electrolyte of the present embodiment has high mass productivity because it is not necessary to heat the raw material at 550 ° C. for 6 days as in Patent Document 1.

  The sulfide solid electrolyte having high ionic conductivity is a sulfide solid electrolyte in which lithium easily moves in the aldilodite type crystal structure. The sulfide solid electrolyte of the present embodiment is a sulfide solid electrolyte in which part of S (sulfur) is deficient, and it is presumed that S deficiency occurs in the non-bridging anion site of the aldilodite type crystal structure. The presence of the defects reduces the amount of lithium in the aldilodite type crystal structure, facilitates diffusion of lithium, and provides high ionic conductivity.

In the case of directly producing a sulfide solid electrolyte containing an aldilodite type crystal structure without passing through an intermediate containing a glass component, it is difficult to obtain a sulfide solid electrolyte having high ionic conductivity. This is because, when the sulfide solid electrolyte is directly produced from the raw material, S (sulfur) is likely to fly during the heat treatment and unreacted lithium halide is likely to remain. Since the unreacted lithium halide remains, halogen is not contained in the aldilodite crystal structure, and a low-conductivity phase such as Li ₃ PS ₄ phase easily precipitates in the obtained sulfide solid electrolyte.
By manufacturing an intermediate containing a glass component and mixing the materials at the atomic level, S does not fly during the heat treatment of the intermediate containing a glass component, no unreacted lithium halide remains, and low conductivity is achieved. Phase precipitation can be prevented.

As the conditions for pulverization and mixing, for example, when a planetary ball mill is used as the pulverizer, the rotation speed may be several tens to several hundreds revolutions / minute, and the treatment may be performed for 0.5 hours to 100 hours. More specifically, in the case of the planetary ball mill (Fritsch Co .: model number P-7) used in the examples of the present application, the rotation speed of the planetary ball mill is preferably 350 rpm or more and 400 rpm or less, more preferably 360 rpm or more and 380 rpm or less.
For example, when a zirconia ball is used as the ball which is a crushing medium, the diameter is preferably 0.2 to 20 mm.

The intermediate body prepared by pulverization and mixing is heat-treated in an atmosphere of an inert gas such as nitrogen or argon. The heat treatment temperature is preferably 350 to 650 ° C, more preferably 400 to 550 ° C.
In the related art (for example, Patent Documents 2 to 5), the raw material mixture is fired under a hydrogen sulfide flow. As a result, sulfur is supplemented at the time of firing, and it is considered that sulfur deficiency due to heating is suppressed. On the other hand, in this embodiment, the heat treatment can be performed in the absence of hydrogen sulfide. In this case, it is considered that the sulfur content is lower than that of the conventional solid electrolyte, and the lack of sulfur occurs in the crystal structure, whereby a sulfide solid electrolyte having high ionic conductivity can be obtained.

For example, when lithium sulfide, phosphorus pentasulfide, or lithium halide is used as the raw material of the sulfide solid electrolyte of the present embodiment, the molar ratio of the input raw materials is lithium sulfide: phosphorus pentasulfide: lithium halide. = 37 to 88: 8 to 25: 0.1 to 50. After mechanical stress is applied to these raw materials to react with each other to form an intermediate, the raw materials are heat treated in the absence of hydrogen sulfide as described above to satisfy the above formulas (1) to (3). A sulfide solid electrolyte can be obtained.
Further, the sulfide solid electrolyte of the present embodiment satisfying the above formulas (1) to (3) can also be obtained by adjusting the type and the molar ratio of the charged raw materials. For example, when phosphorus sulfide is used, some or all of phosphorus pentasulfide (P ₂ S ₅ ) may be phosphorus trisulfide (P ₂ S ₃ ). In addition, it is possible to use elemental phosphorus (P) as the phosphorus source, or to use metallic lithium (Li) as the lithium source. In each case, sulfur is relatively reduced from the stoichiometric ratio calculated from the three raw materials Li ₂ S, P ₂ S ₅ , and LiX.

  The sulfide solid electrolyte of this embodiment can be used for a solid electrolyte layer of a lithium ion secondary battery or the like, a positive electrode, a negative electrode, or the like.

[Electrode mixture]
An electrode mixture according to an embodiment of the present invention contains the above-described sulfide solid electrolyte of the present invention and an active material. Alternatively, it is produced by the sulfide solid electrolyte of the present invention. When a negative electrode active material is used as the active material, it becomes a negative electrode mixture. On the other hand, when a positive electrode active material is used, it becomes a positive electrode mixture.

-Negative electrode composite material A negative electrode composite material can be obtained by mixing a negative electrode active material with the sulfide solid electrolyte of the present invention.
As the negative electrode active material, for example, a carbon material, a metal material or the like can be used. A complex composed of two or more of these may also be used. Further, a negative electrode active material developed in the future can also be used.
The negative electrode active material preferably has electronic conductivity.
Examples of the carbon material include graphite (for example, artificial graphite), graphite carbon fiber, resin-fired carbon, pyrolysis vapor-phase growth carbon, coke, mesocarbon microbeads (MCMB), furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon. Fibers, vapor grown carbon fibers, natural graphite, non-graphitizable carbon and the like can be mentioned.
Examples of the metal material include simple metals, alloys, and metal compounds. Examples of the metal simple substance include metal silicon, metal tin, metal lithium, metal indium, and metal aluminum. Examples of the alloy include alloys containing at least one of silicon, tin, lithium, indium, and aluminum. Examples of the metal compound include metal oxides. The metal oxide is, for example, silicon oxide, tin oxide or aluminum oxide.

The mixing ratio of the negative electrode active material and the solid electrolyte is preferably negative electrode active material: solid electrolyte = 95% by weight: 5% by weight to 5% by weight: 95% by weight, and 90% by weight: 10% by weight to 10% by weight: 90% by weight %, More preferably 85% by weight: 15% by weight to 15% by weight: 85% by weight.
If the content of the negative electrode active material in the negative electrode mixture is too small, the electric capacity becomes small. In addition, when the negative electrode active material has electron conductivity and does not contain a conductive auxiliary agent or contains only a small amount of conductive auxiliary agent, the electron conductivity (electron conductive path) in the negative electrode is lowered and It is considered that there is a possibility that the characteristics may be lowered, or the utilization factor of the negative electrode active material may be lowered, and the electric capacity may be lowered. On the other hand, if the content of the negative electrode active material in the negative electrode mixture is too large, the ion conductivity (ion conduction path) in the negative electrode may decrease, the rate characteristics may deteriorate, and the utilization rate of the negative electrode active material may decrease, resulting We think that the capacity may decrease.

The negative electrode mixture may further contain a conductive additive.
When the negative electrode active material has low electron conductivity, it is preferable to add a conductive additive. The conductive additive needs to have conductivity, and its electronic conductivity is preferably 1 × 10 ³ S / cm or more, more preferably 1 × 10 ⁵ S / cm or more.
Specific examples of the conductive aid, preferably carbon material, nickel, copper, aluminum, indium, silver, cobalt, magnesium, lithium, chromium, gold, ruthenium, platinum, beryllium, iridium, molybdenum, niobium, osmium, rhodium, A substance containing at least one element selected from the group consisting of tungsten and zinc, and more preferably a carbon element having high conductivity, or a carbon material other than carbon element; nickel, copper, silver, cobalt, magnesium, lithium, ruthenium. , A simple substance, a mixture or a compound containing gold, platinum, niobium, osmium or rhodium.
Specific examples of the carbon material include carbon black such as Ketjen black, acetylene black, denka black, thermal black, and channel black; graphite, carbon fiber, activated carbon, and the like. These may be used alone or in combination of two or more. It is possible. Of these, acetylene black, denka black, and Ketjen black, which have high electron conductivity, are preferable.

  When the negative electrode mixture contains a conduction aid, the content of the conduction aid in the mixture is preferably 1 to 40% by mass, more preferably 2 to 20% by mass. It is considered that when the content of the conductive additive is too small, the electron conductivity of the negative electrode may be lowered and the rate characteristic may be lowered, or the utilization factor of the negative electrode active material may be lowered, and the electric capacity may be lowered. On the other hand, if the content of the conductive additive is too large, the amount of the negative electrode active material and / or the amount of the solid electrolyte becomes small. It is assumed that the electric capacity decreases as the amount of the negative electrode active material decreases. Further, it is considered that when the amount of the solid electrolyte is reduced, the ionic conductivity of the negative electrode may be lowered, the rate characteristics may be lowered, or the utilization rate of the negative electrode active material may be lowered, and the electric capacity may be lowered.

A binder may be further included in order to tightly bind the negative electrode active material and the solid electrolyte to each other.
Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluorine-containing resins such as fluororubber, thermoplastic resins such as polypropylene and polyethylene, ethylene-propylene-diene rubber (EPDM), sulfonated EPDM, natural butyl rubber (NBR) and the like can be used alone or as a mixture of two or more kinds. Further, it is also possible to use an aqueous dispersion of cellulose-based or styrene-butadiene rubber (SBR) which is an aqueous binder.

The negative electrode mixture can be produced by mixing the solid electrolyte, the negative electrode active material, and any conductive auxiliary agent and / or binder.
The mixing method is not limited, for example, a mortar, a ball mill, a bead mill, a jet mill, a planetary ball mill, a vibrating ball mill, a sand mill, a dry mixing by using a cutter mill; and, after dispersing the raw materials in an organic solvent, a mortar, Wet mixing can be applied in which a ball mill, a bead mill, a planetary ball mill, a vibrating ball mill, a sand mill, and a fill mix are used, and then the solvent is removed. Of these, wet mixing is preferable because it does not destroy the negative electrode active material particles.

-Positive electrode composite material A positive electrode composite material can be obtained by compounding the solid electrolyte of the present invention with a positive electrode active material.
The positive electrode active material is a material capable of inserting and releasing lithium ions, and a known material as a positive electrode active material in the field of batteries can be used. Further, a positive electrode active material developed in the future can also be used.

Examples of the positive electrode active material include metal oxides and sulfides. Sulfides include metal sulfides and non-metal sulfides.
The metal oxide is, for example, a transition metal oxide. Specifically, V ₂ O ₅ , V ₆ O ₁₃ , LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , Li (Ni _a Co _b Mn _c ) O ₂ (where 0 <a <1, _{0 <b <1,0 <c <} 1, a + b + c = 1), LiNi 1-Y Co Y O 2, LiCo 1-Y Mn Y O 2, LiNi 1-Y Mn Y O 2 ( where, 0 ≦ Y _{<1), Li (Ni a} Co b Mn c) O 4 (0 <a <2,0 <b <2,0 <c <2, a + b + c = 2), LiMn 2-Z Ni Z O 4, LiMn 2 _-Z Co _Z O _{4 (where, 0 <Z <2),} LiCoPO 4, LiFePO 4, CuO, Li (Ni a Co b Al c) O 2 ( where, 0 <a <1,0 <b < 1, 0 <c <1, a + b + c = 1) and the like.
Examples of the metal sulfide include titanium sulfide (TiS ₂ ), molybdenum sulfide (MoS ₂ ), iron sulfide (FeS, FeS ₂ ), copper sulfide (CuS), nickel sulfide (Ni ₃ S ₂ ), and the like.
Other examples of the metal oxide include bismuth oxide (Bi ₂ O ₃ ), bismuth lead oxide (Bi ₂ Pb ₂ O ₅ ), and the like.
Examples of non-metal sulfides include organic disulfide compounds and carbon sulfide compounds.
In addition to the above, niobium selenide (NbSe ₃ ), metallic indium, and sulfur can also be used as the positive electrode active material.

The positive electrode mixture may further contain a conductive auxiliary agent.
The conductive additive is the same as the negative electrode mixture.

  The mixing ratio of the solid electrolyte and the positive electrode active material of the positive electrode mixture, the content of the conductive additive, and the method for producing the positive electrode mixture are the same as those of the above-described negative electrode mixture.

[Lithium-ion battery]
A lithium ion battery according to one embodiment of the present invention includes at least one of the above-described sulfide solid electrolyte of the present invention and an electrode mixture. Alternatively, it is manufactured by at least one of the sulfide solid electrolyte and the electrode mixture of the present invention.
Although the structure of the lithium ion battery is not limited, it generally has a structure in which a negative electrode layer, an electrolyte layer, and a positive electrode layer are laminated in this order. Hereinafter, each layer of the lithium ion battery will be described.

(1) Negative Electrode Layer The negative electrode layer is preferably a layer manufactured from the negative electrode mixture material of the present invention.
Alternatively, the negative electrode layer is preferably a layer containing the negative electrode mixture material of the present invention.
The thickness of the negative electrode layer is preferably 100 nm or more and 5 mm or less, more preferably 1 μm or more and 3 mm or less, and further preferably 5 μm or more and 1 mm or less.
The negative electrode layer can be manufactured by a known method, for example, a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

(2) Electrolyte layer The electrolyte layer is a layer containing a solid electrolyte or a layer manufactured from the solid electrolyte. The solid electrolyte is not limited, but is preferably the sulfide solid electrolyte of the present invention.
The electrolyte layer may consist only of a solid electrolyte, and may further contain a binder. As the binder, the same binder as the binder for the negative electrode mixture of the present invention can be used.

The thickness of the electrolyte layer is preferably 0.001 mm or more and 1 mm or less.
The solid electrolyte of the electrolyte layer may be fused. Fusing means that a part of the solid electrolyte particles is dissolved and the melted part is integrated with other solid electrolyte particles. Further, the electrolyte layer may be a plate-like body of a solid electrolyte, and the plate-like body also includes a case where a part or all of the solid electrolyte particles are dissolved to form a plate-like body.
The electrolyte layer can be produced by a known method, for example, a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

(3) Positive Electrode Layer The positive electrode layer is a layer containing a positive electrode active material, and is preferably a layer containing the positive electrode mixture of the present invention or a layer produced from the positive electrode mixture of the present invention.
The thickness of the positive electrode layer is preferably 0.01 mm or more and 10 mm or less.
The positive electrode layer can be manufactured by a known method, for example, a coating method or an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

(4) Current Collector The lithium-ion battery of this embodiment preferably further comprises a current collector. For example, the negative electrode current collector is provided on the opposite side of the negative electrode layer from the electrolyte layer side, and the positive electrode current collector is provided on the opposite side of the positive electrode layer from the electrolyte layer side.
As the current collector, a plate-like body or a foil-like body made of copper, magnesium, stainless steel, titanium, iron, cobalt, nickel, zinc, aluminum, germanium, indium, lithium, or an alloy thereof can be used.

The lithium-ion battery of this embodiment can be manufactured by bonding and joining the above-mentioned members. As a method of joining, there are a method of laminating each member and pressurizing / compressing it, a method of pressing between two rolls (roll to roll), and the like.
Alternatively, the bonding surface may be bonded via an active material having ion conductivity or an adhesive material that does not inhibit ion conductivity.
In the joining, heat fusion may be performed within a range in which the crystal structure of the solid electrolyte does not change.
The lithium ion battery of this embodiment can also be manufactured by sequentially forming the above-mentioned members. It can be manufactured by a known method, for example, a coating method, an electrostatic method (electrostatic spray method, electrostatic screen method, etc.).

Hereinafter, the present invention will be described in more detail with reference to Examples.
The evaluation method is as follows.
(1) Ionic Conductivity Measurement and Electronic Conductivity Measurement The sulfide solid electrolyte produced in each example was filled in a tablet molding machine, and a pressure of 407 MPa (press display value 22 MPa) was applied using a mini press machine to obtain a molded body. did. Carbon was placed on both sides of the molded body as an electrode, and pressure was again applied by a tablet molding machine to produce a molded body for measurement (about 10 mm in diameter and 0.1 to 0.2 cm in thickness). The ionic conductivity of this molded body was measured by AC impedance measurement. The value of the conductivity at 25 ° C. was adopted.
In the measuring method of ionic conductivity used in this example, if the ionic conductivity is less than 1.0 × 10 ⁻⁶ S / cm, the ionic conductivity cannot be measured accurately, and therefore the measurement is impossible. And
The electronic conductivity of this molded product was measured by direct current electrical measurement. The value at 25 ° C. was adopted as the value of electron conductivity. When the electron conductivity when a voltage of 5 V was applied was less than 1.0 × 10 ⁻⁶ S / cm, the electron conductivity was determined to be unmeasurable.

(2) X-ray Diffraction (XRD) Measurement From the powder of the sulfide solid electrolyte produced in each example, a circular pellet having a diameter of 10 mm and a height of 0.1 to 0.3 cm was formed into a sample. This sample was measured without contact with air using an airtight XRD holder. The 2θ position of the diffraction peak was determined by the center of gravity method using the XRD analysis program JADE.
It was carried out under the following conditions using a powder X-ray diffraction measuring device SmartLab manufactured by Rigaku Corporation.
Tube voltage: 45 kV
Tube current: 200 mA
X-ray wavelength: Cu-Kα ray (1.5418 °)
Optical system: parallel beam method Slit configuration: solar slit 5 °, incident slit 1 mm, light receiving slit 1 mm
Detector: Scintillation counter Measurement range: 2θ = 10-60 deg
Step width, scan speed: 0.02 deg, 1 deg / min In the analysis of the peak position for confirming the existence of the crystal structure from the measurement results, the XRD analysis program JADE was used to draw a baseline by cubic approximation, The position was determined.
In terms of peak intensity, one peak intensity of the aldilodite type crystal structure present at 2θ = 29.7 ± 0.5 deg, Li ₃ present at 2θ = 17.6 ± 0.4 deg and 18.1 ± 0.4 deg. The two peak intensities of the PS ₄ crystal structure were analyzed by the following procedure, and the intensity ratio was calculated.
Smoothing was performed by moving average of 5 points of the measured data, and the lowest intensity point between 16.5 to 17.5 deg was used as the background and subtracted from the measured data. Then, the maximum value of the actual measurement data between the maximum values of the actual measurement data of 17.0 to 17.8 deg and 17.9 to 18.5 deg was calculated, and the smaller peak intensity was calculated as the peak intensity of the Li ₃ PS ₄ crystal structure. Used as. In addition, the peak intensity of the aldilodite type crystal structure was calculated using the maximum value of the measured data of 29.0 to 32.0 deg as the peak intensity.

(3) ICP measurement The powder of the sulfide solid electrolyte produced in each example was weighed and collected in a vial in an argon atmosphere. A KOH alkaline aqueous solution was placed in a vial, the sample was dissolved while paying attention to the collection of sulfur content, and diluted appropriately to obtain a measurement solution. The composition was determined by measuring this with a Paschen-Lunge ICP-OES device (SPECTRO ARCOS manufactured by SPECRO).
The calibration curve solutions were prepared by using Li, P, and S as 1000 mg / L standard solutions for ICP measurement, Cl and Br as 1000 mg / L standard solutions for ion chromatography, and I as potassium iodide (special grade reagent). .
Two measurement solutions were prepared for each sample, each measurement solution was measured 5 times, and the average value was calculated. The composition was determined by averaging the measured values of the two measurement solutions.

Production example 1
(Production of lithium sulfide (Li ₂ S))
A 500 mL separable flask equipped with a stirrer was charged with 200 g of LiOH anhydride (manufactured by Honjo Chemical Co., Ltd.) dried under an inert gas. The temperature was raised under a nitrogen stream, and the internal temperature was maintained at 200 ° C. The nitrogen gas was switched to hydrogen sulfide gas (Sumitomo Seika), the flow rate was set to 500 mL / min, and the LiOH anhydride and hydrogen sulfide were reacted.
Water generated by the reaction was condensed and collected by a condenser. When the reaction was performed for 6 hours, 144 mL of water was recovered. The reaction was continued for another 3 hours, but no generation of water was observed.
The product powder was collected and measured for purity and XRD. As a result, the purity was 98.5%, and a peak pattern of Li ₂ S was confirmed by XRD.

Example 1
Use lithium sulfide (purity 98.5%), diphosphorus pentasulfide (manufactured by Thermophos, purity 99.9% or more) and lithium chloride (manufactured by Sigma-Aldrich, purity 99%) manufactured in Preparation Example 1 as starting materials. (Hereinafter, the purity of each starting material is the same in all the examples). The molar ratio (Li ₂ S: P ₂ S ₅ : LiCl) of lithium sulfide (Li2S), phosphorus pentasulfide (P2S5) and lithium chloride (LiCl) is set to 46.8: 12.7: 40.5. , Each raw material was mixed. Specifically, 0.483 g of lithium sulfide, 0.632 g of diphosphorus pentasulfide, and 0.385 g of lithium chloride were mixed to obtain a raw material mixture.

The raw material mixture and 30 g of zirconia balls having a diameter of 10 mm were placed in a planetary ball mill (Fritsch Corp .: Model No. P-7) zirconia pot (45 mL) and completely sealed. Argon atmosphere was used in the pot. A planetary ball mill was operated at a rotation speed of 370 rpm for 60 hours (mechanical milling) to obtain a glassy powder (intermediate). The results of XRD evaluation of the intermediate are shown in FIG. It was confirmed from the obtained XRD pattern that most of the glass was glass. In the XRD data of the intermediate, only the peaks of the raw materials Li ₂ S and LiCl were observed.
About 1.5 g of the above-mentioned intermediate powder was packed in a Tammann tube (PT2, made by Tokyo Glass Equipment Co., Ltd.) in a glove box under Ar atmosphere, the mouth of the Tammann tube was closed with quartz wool, and further made of SUS. The container was sealed to prevent air from entering. Thereafter, the sealed container was placed in an electric furnace (FUW243PA, manufactured by Advantech) and heat-treated. Specifically, the temperature was raised from room temperature to 500 ° C at a rate of 2.5 ° C / min (the temperature was raised to 500 ° C in 3 hours), and the temperature was kept at 500 ° C for 8 hours. Then, the mixture was gradually cooled to obtain a sulfide solid electrolyte.

The ionic conductivity (σ) of the sulfide solid electrolyte was 6.9 mS / cm. The electronic conductivity was less than 10 ⁻⁶ S / cm.
The XRD pattern of the sulfide solid electrolyte is shown in FIG. At 2θ = 15.5, 18.0, 25.5, 30.0, 31.4, 45.2, and 48.0 deg, peaks derived from the aldyrodiite type crystal structure were observed. On the other hand, the peak derived from the Li ₃ PS ₄ crystal structure of 17.6 ± 0.4 deg was not observed.
The sulfide solid electrolyte was subjected to ICP analysis to measure the molar ratio of each element. The results are shown in Table 1.

Example 2
A sulfide solid electrolyte was prepared and evaluated in the same manner as in Example 1 except that the treatment time by the planetary ball mill was 15 hours. The results are shown in Table 1.
As a result of XRD measurement, peaks derived from the aldilodite type crystal structure were observed at 2θ = 15.6, 18.0, 25.6, 30.1, 31.5, 45.2, and 48.1 deg. On the other hand, no peak derived from the Li ₃ PS ₄ crystal structure was observed.

Examples 3-15, Comparative Examples 1-6
A sulfide solid electrolyte was prepared and evaluated in the same manner as in Example 2 except that the raw material composition, the conditions of mechanical milling, and the heat treatment conditions of the intermediate were changed as shown in Table 2. The results are shown in Table 1.
In addition, regarding the measurement result of XRD, in Example 3, 2θ = 15.1, 18.0, 25.4, 29.9, 31.3, 44.9, and 47.8 deg are derived from the aldyrodite type crystal structure. A peak was observed. On the other hand, no peak derived from the Li ₃ PS ₄ crystal structure was observed.
In Comparative Example 1, peaks derived from the aldilodite type crystal structure were observed at 2θ = 15.5, 17.7, 25.5, 30.0, 31.4, 44.8 and 48.0 deg. On the other hand, no peak derived from the Li ₃ PS ₄ crystal structure was observed.

Comparative Example 7
The molar ratio (Li ₂ S: P ₂ S ₅ : LiCl) of lithium sulfide (Li ₂ S), phosphorus pentasulfide (P ₂ S ₅ ) and lithium chloride (LiCl) used in Example 1 was 1.9: The respective raw materials were mixed so that the ratio became 0.5: 1.6.
The raw material mixture and 30 g of zirconia balls having a diameter of 10 mm were placed in a planetary ball mill (Fritsch Corp .: Model No. P-7) zirconia pot (45 mL) and completely sealed. Argon atmosphere was used in the pot. The raw material powders were mixed in a planetary ball mill to such an extent that the crystallinity of the raw material powders could be maintained to obtain a mixed powder.
The XRD pattern of the obtained mixed powder is shown in FIG. In the obtained XRD pattern, peaks of the raw materials Li ₂ S, P ₂ S ₅ , and LiCl were confirmed, and the crystallinity of the raw material powder was maintained.

  Approximately 1.5 g of the mixed powder was packed in a glass tube with a sealing function in a glove box under Ar atmosphere, and the tip of the glass tube was sealed with a dedicated jig so that air could not enter. Then, the glass tube was set in the electric furnace. The dedicated jig was inserted into a joint in the electric furnace, connected to a gas flow pipe, and heat-treated while flowing hydrogen sulfide at 20 mL / min. Specifically, the temperature was raised from room temperature to 500 ° C at a rate of 2.5 ° C / min (the temperature was raised to 500 ° C in 3 hours), and the temperature was kept at 500 ° C for 4 hours. Then, the mixture was gradually cooled to obtain a sulfide solid electrolyte.

  The obtained sulfide solid electrolyte was subjected to ICP analysis to measure the molar ratio of each element. Also, the ionic conductivity was measured. As a result, a (Li / P) = 5.4, b (S / P) = 4.4, c (Cl / P) = 1.6, and the ionic conductivity (σ) is 2.7 mS /. It was cm.

Example 16
The raw materials used in Example 1, lithium sulfide (Li ₂ S), phosphorus pentasulfide (P ₂ S ₅ ), and lithium chloride (LiCl), and lithium iodide (LiI: manufactured by Sigma-Aldrich Co., purity 99). %) Was used as the raw material. The raw materials were mixed so that the molar ratio of these raw materials (Li ₂ S: P ₂ S ₅ : LiCl: LiI) was 46.8: 12.7: 38.0: 2.5. Specifically, 0.467 g of lithium sulfide, 0.610 g of diphosphorus pentasulfide, 0.349 g of lithium chloride and 0.074 g of lithium iodide were mixed to obtain a raw material mixture.
Using the obtained raw material mixture, a sulfide solid electrolyte was produced under the same mechanical milling conditions and heat treatment conditions as in Example 1. The ionic conductivity (σ) of the obtained sulfide solid electrolyte was 5.5 mS / cm. The electronic conductivity was less than 10 ⁻⁶ S / cm.
The obtained sulfide solid electrolyte was subjected to XRD measurement, and as a result, a peak derived from an aldilodite type crystal structure was observed.
As a result of ICP analysis, the molar ratio a (Li / P) was 5.38, the molar ratio b (S / P) was 4.36, and the molar ratio c ((Cl + I) / P) was 1.70.

Although some of the embodiments and / or examples of the present invention have been described in detail above, those skilled in the art may substantially without departing from the novel teachings and effects of the present invention. It is easy to make many changes to the embodiment. Therefore, many of these modifications are within the scope of the invention.
The entire contents of the Japanese application specification which is the basis of the priority of Paris in the present application are incorporated herein.

Claims (10)

Lithium, phosphorus, sulfur,
Including one or more elements X selected from the group consisting of chalcogen elements other than sulfur and halogen elements,
Including an aldilodite type crystal structure,
The molar ratio a (Li / P) of lithium to phosphorus, the molar ratio b (S / P) of sulfur to phosphorus, and the molar ratio c (X / P) of the element X to phosphorus are represented by the following formulas (1) to A sulfide solid electrolyte that satisfies (3).
5.0 ≦ a ≦ 7.1 (1)
1.0 <ab = 1.5 (2)
6.5 ≦ a + c <7.1 (3)
(In the formula, b> 0 and c> 0 are satisfied.) The sulfide solid electrolyte according to claim 1, which satisfies the composition represented by the following formula (4).
Li _a (P _1-z M _z ) S _b X _c (4)
(In the formula, M is one or more elements selected from the group consisting of Si, Ge, Sn, Pb, B, Al, Ga, As, Sb and Bi, and X is F, Cl, Br, I. , O, Se, and Te are one or more elements selected from the group consisting of a to c satisfying the above formulas (1) to (3), and z is 0 ≦ z ≦ 0.3.   The sulfide solid electrolyte according to claim 2, wherein the X is one or more halogen elements selected from F, Cl, Br and I.   The sulfide solid electrolyte according to any one of claims 1 to 3, which has a diffraction peak at 2θ = 25.2 ± 0.5 deg and 29.7 ± 0.5 deg in powder X-ray diffraction using CuKα ray.   Further, in powder X-ray diffraction using CuKα ray, 2θ = 15.3 ± 0.5 deg, 17.7 ± 0.5 deg, 31.1 ± 0.5 deg, 44.9 ± 0.5 deg and 47.7. The sulfide solid electrolyte according to claim 4, which has at least one of diffraction peaks of ± 0.5 deg.   The sulfide solid electrolyte according to claim 4 or 5, wherein the range of the diffraction peak is ± 0.3 deg of the median value.   The sulfide solid electrolyte according to claim 1, which has an ionic conductivity of 5.1 mS / cm or more.   Does the powder X-ray diffraction using CuKα ray have a diffraction peak at 2θ = 17.6 ± 0.4 deg and 2θ = 18.1 ± 0.4 deg (not a diffraction peak due to an aldilodite type crystal structure)? The sulfide solid electrolyte according to any one of claims 1 to 7, which, when included, satisfies the following formula (5).
        0 <I _A / I _B <0.05 (5)
(In the formula, I _A Represents the intensity of the diffraction peak of 2θ = 17.6 ± 0.4 deg and 2θ = 18.1 ± 0.4 deg which is not the diffraction peak of the aldyrodiite type crystal structure, and I _B Represents the intensity of the diffraction peak at 2θ = 29.7 ± 0.5 deg. ) Electrode mixture comprising a sulfide solid electrolyte according, the active material in any one of claims 1-8. Lithium ion battery comprising at least one of the electrodes cause material according to sulfide solid electrolyte and claim 9 according to any one of claims 1-8.